It is well known in the art of fine fragrance that, when an alcoholic perfume is applied onto the skin, the volatile top notes are stripped preferentially by ethanol evaporation while the more heavy notes exhibit superior tenacity, i.e., they are released from the skin over a longer period of time. As a consequence, many attempts have been made to improve the tenacity or extend the diffusion time of a perfume intended for an application on a support such as the skin, particularly as regards the most volatile ingredients of the fragrance. The use of so-called “perfume fixatives” in perfume formulations has been widely described and usually consists in adding to a perfume composition one or more ingredients capable of chemically modifying the structure of the composition itself, so as to retain the perfuming ingredients in the structure and slow down their release into the ambient air.
In particular, some patent literature discloses the use of ingredients which have the effect of gelling or even solidifying the compositions to which they are added, thus slowing down the diffusion in the air of particularly volatile ingredients. For instance, European patent application EP181401 describes a gelatinised perfume formed by mixing a mixture formed by adding a perfume oil to an alcohol solution containing from 1 to 5% of hydroxypropylcellulose, with a saturated solution of dibenzylidenesorbital in N-methyl-2-pyrrolidone, to form a gel-like solid mixture in which the alcohol is inactivated and thus the fragrance persistent. In this process, the volatility of the alcohol is reduced by the incorporation of hydroxypropylcellulose and, at the same time, the gelatinisation activated by the presence of dibenzylidene-sorbitol allows to control the scattering of the fragrance. On the other hand, European patent application EP 857481 describes a composition, in the form of a gel, associating an organosiloxane compound together with a hydrocarbonated, siliconated or fluorinated oil. These additives are added in large quantities and contribute to the formation of a gel.
These documents, disclosing compositions that retain the perfume by way of gelatinisation or solidification, do not allow to prepare perfumes of low viscosity capable of being sprayed.
European patent application EP 700677 approaches the same problematic of fixing a perfume and/or extending the perfume release from a dermatological or cosmetic composition. More particularly, said document describes the use in such compositions of a vegetable compound consisting of a vegetable extract combined with a vegetable gum. In that disclosure, it is mentioned that a solvent such as ethanol must be present in low quantity in the composition to avoid the release of an important amount of perfume all at once. This limitation prevents such compositions from being used in the field of fine perfumery, wherein perfume solutions are essentially based on the use of very large quantities of alcohol in order to solubilize the perfuming ingredients.
On the other hand, U.S. Pat. No. 6,172,037 discloses a perfume fixative constituted by the association of three particular ingredients, namely polyvinylpyrrolidone, hydroxypropyl cellulose and a non volatile hydrophobic oil, the two first ingredients being present in quantities below 0.5% by weight of the perfume-containing product. The perfumes thus prepared are particularly useful in applications such as deodorants, deo-colognes and antiperspirants. In this document, the combination of the three ingredients is essential to enhance the fragrance life, but the amounts of the latter are limited, as they are discernible by the user when used in high quantities. All the examples given in said document are perfume formulations for an intended use in deodorant type applications and thus comprise a limited amount of perfume, usually from 1 to 2% by weight of perfume relative to the total weight of the final composition. Therefore, it is very likely that the disclosed fixative ingredients are not suitable for fine fragrance or perfume formulations that comprise higher quantities of perfume, as the fixative would then have to be used in higher quantities and would thus be detectable by the user.
Therefore, in view of the existing prior art related to “fixative ingredients” capable of extending the diffusion of volatile ingredients present in perfumes, the compositions provided up-to-date still have many limitations and, in particular, none of the prior art solutions are suitable for an application in fine perfumery, i.e., applications wherein the perfume formulation must be transparent, sprayable, comprises a high quantity of alcohol and a high quantity of perfuming ingredients. The present invention now provides a solution to the above mentioned problems.